The present invention is directed to a pressureless infeed conveyor table for use with a control means for forming predetermined spaces between articles on a conveyor line in order to create a uniform column for further processing, particularly in a packaging process. The pressureless infeed conveyor table has a direct drive means for moving the first carriage which reduces stress on the sprocket assembly, thereby lessening the amount of mass required to comprise the sprocket assembly. The lightweight sprocket assembly allows an increase in the speed and efficiency at which the carriage can reciprocate, resulting in increased production speed.
In an automated packaging process, it is desirable to arrange the articles on the infeed conveying line in a uniform column with a predetermined spacing between them. However, there is a tendency for the articles to be positioned at irregular intervals along the conveyor.
If the articles being processed are sticky, the problem is compounded where even the slightest irregular spacing can cause unwanted article accumulations to occur on the conveyor. These accumulations can require that the conveying line be shut down to correct the problem. These shutdowns increase production time and production costs, as well. Consequently, there is a need for an infeed conveyor table that can quickly and efficiently form articles on a conveyor line into a uniform column having a predetermined spacing.
It is known that a predetermined distance can be created between articles moving in a column by simultaneously changing the effective lengths of a supply belt and a downstream removal belt as each article moves from the former to the latter. The effective lengths of the belts are varied by reciprocating carriages which are moved back and forth by a sprocket assembly driven by a servomotor.
The sprocket assembly must be strong enough to overcome the inertial forces created by the weight of the carriages as well as the weight of the assembly itself in order to move. Consequently, the sprocket assemblies of the prior art are of a large mass and weight. The speed of the carriages is dependent on the speed at which the sprocket assembly can be driven. A heavy sprocket assembly, such as required by the prior art infeed devices, is cumbersome and is forced to move at a slower rate of speed. Therefore, the speed of the carriage is reduced and the resultant operating speed of the infeed device is diminished by the weight of the sprocket assembly in the prior art devices.
For the foregoing reasons, there is a need for a pressureless infeed conveyor table having a direct drive means for the reciprocating carriages in order to provide a faster and more efficient device for use in a system which spaces articles in a uniform column with predetermined distance between the articles.